基于Taro + React 实现微信小程序半圆滑块组件、半圆进度条、弧形进度条、半圆滑行轨道（附源码）

效果：

功能点：

1、四个档位

2、可点击加减切换档位

3、可以点击区域切换档位

4、可以滑动切换档位

目的：

给大家提供一些实现思路，找了一圈，一些文章基本不能直接用，错漏百出，代码还藏着掖着，希望可以帮到大家

代码

ts的写法风格

index.tsx     

import { View, ITouchEvent, BaseTouchEvent } from '@tarojs/components'
import Taro from '@tarojs/taro'
import { useState } from 'react'
import styles from './index.module.less'
import classNames from 'classnames'
import { debounce } from '~/utils/util'enum ANGLES {ANGLES_135 = -135,ANGLES_90 = -90,ANGLES_45 = -45,ANGLES_0 = 0
}enum MODE_VALUE {MODE_1 = 1,MODE_2 = 2,MODE_3 = 3,MODE_4 = 4
}const HalfCircle = () => {const [state, setState] = useState({originAngle: ANGLES.ANGLES_135,isTouch: false,val: MODE_VALUE.MODE_1,originX: 0,originY: 0})/** 半圆的半径 */const RADIUS = 150/** 半径的一半 */const RADIUS_HALF = RADIUS / 2/** 4/3 圆的直径 */const RADIUS_THIRD = RADIUS_HALF * 3/** 直径 */const RADIUS_DOUBLE = RADIUS * 2/** 误差 */const DEVIATION = 25/** 是否开启点击振动 */const isVibrateShort = trueconst getAngle = () => {return {transform: `rotate(${state.originAngle}deg)`,transition: `all ${state.isTouch ? ' 0.2s' : ' 0.55s'}`}}/*** 根据坐标判断是否在半圆轨道上，半圆为RADIUS，误差为DEVIATION* @param pageX* @param pageY*/const isInHalfCircleLine = (pageX: number, pageY: number, deviation?: number) => {const DEVIATION_VALUE = deviation || DEVIATIONconst squareSum = (pageX - RADIUS) * (pageX - RADIUS) + (pageY - RADIUS) * (pageY - RADIUS)const min = (RADIUS - DEVIATION_VALUE) * (RADIUS - DEVIATION_VALUE)const max = (RADIUS + DEVIATION_VALUE) * (RADIUS + DEVIATION_VALUE)return squareSum >= min && squareSum <= max}/** 根据做标点，获取档位 0 -> 4, -45 -> 3, -90 -> 2, -135 -> 1，从而获取旋转的角度 */const setGear = (pageX: number, pageY: number) => {let val = state.vallet originAngle = state.originAngleif (isInHalfCircleLine(pageX, pageY)) {if (pageX > 0 && pageX <= RADIUS_HALF) {val = MODE_VALUE.MODE_1originAngle = ANGLES.ANGLES_135} else if (pageX > RADIUS_HALF && pageX <= RADIUS) {val = MODE_VALUE.MODE_2originAngle = ANGLES.ANGLES_90} else if (pageX > RADIUS && pageX <= RADIUS_THIRD) {val = MODE_VALUE.MODE_3originAngle = ANGLES.ANGLES_45} else {val = MODE_VALUE.MODE_4originAngle = ANGLES.ANGLES_0}}if (state.val === val) returnsetState((old) => {return {...old,originAngle,val}})if (isVibrateShort) {setTimeout(() => {Taro.vibrateShort()}, 200)}}/*** 滑动比较细腻,根据x轴坐标，calcX判断是否前进还是后退* @param pageX* @param pageY*/const setGearSibler = (pageX: number, pageY: number) => {let val = state.vallet originAngle = state.originAngleconst calcX = pageX - state.originX/** 把误差值增加，方便滑动 */if (isInHalfCircleLine(pageX, pageY, 50)) {if (pageX > 0 && pageX <= RADIUS_HALF) {if (calcX > 0) {/** 向前滑动，就前进一个档位 */val = MODE_VALUE.MODE_2originAngle = ANGLES.ANGLES_90} else {/** 向后滑动，就后退一个档位 */val = MODE_VALUE.MODE_1originAngle = ANGLES.ANGLES_135}} else if (pageX > RADIUS_HALF && pageX <= RADIUS) {if (calcX > 0) {val = MODE_VALUE.MODE_2originAngle = ANGLES.ANGLES_90} else {val = MODE_VALUE.MODE_1originAngle = ANGLES.ANGLES_135}} else if (pageX > RADIUS && pageX <= RADIUS_THIRD) {if (calcX > 0) {val = MODE_VALUE.MODE_3originAngle = ANGLES.ANGLES_45} else {val = MODE_VALUE.MODE_2originAngle = ANGLES.ANGLES_90}} else {if (calcX > 0) {val = MODE_VALUE.MODE_4originAngle = ANGLES.ANGLES_0} else {val = MODE_VALUE.MODE_3originAngle = ANGLES.ANGLES_45}}}setState((old) => {return {...old,originAngle,val}})}/*** 获取正确的坐标点* @param pageX* @param pageY* @returns*/const getRealXY = (pageX: number,pageY: number): Promise<{realX: numberrealY: number}> => {return new Promise((resolve) => {Taro.createSelectorQuery().select('#sliderBgcId').boundingClientRect((rect) => {const { left, top } = rect/** 获取真实的做标点 */const realX = pageX - leftconst realY = pageY - topresolve({realX,realY})}).exec()})}const onTouchEnd = (event: BaseTouchEvent<any>) => {setState((old) => {return {...old,isTouch: false}})}const onTouchMove = debounce(async (event: BaseTouchEvent<any>) => {const { pageX, pageY } = event.changedTouches[0]const { realX, realY } = await getRealXY(pageX, pageY)if (isInHalfCircleLine(realX, realY)) {setGearSibler(realX, realY)}}, 100)const onTouchStart = async (event: BaseTouchEvent<any>) => {const { pageX, pageY } = event.changedTouches[0]const { realX, realY } = await getRealXY(pageX, pageY)setState((old) => {return {...old,originX: realX,originY: realY,isTouch: true}})}/** 点击设置档位 */const onHandleFirstTouch = async (event: BaseTouchEvent<any>) => {const { pageX, pageY } = event.changedTouches[0]const { realX, realY } = await getRealXY(pageX, pageY)if (isInHalfCircleLine(realX, realY)) {setGear(realX, realY)}}const lose = () => {if (state.isTouch) returnif (state.val === 1) return Taro.showToast({title: '最低只能1挡',icon: 'error',duration: 2000})setState((old) => {return {...old,originAngle: state.originAngle - 45,val: state.val - 1}})if (isVibrateShort) {Taro.vibrateShort()}}const add = () => {if (state.isTouch) returnif (state.val === 4) return Taro.showToast({title: '最高只能4挡',icon: 'error',duration: 2000})setState((old) => {return {...old,originAngle: state.originAngle + 45,val: state.val + 1}})if (isVibrateShort) {Taro.vibrateShort()}}return (<ViewclassName={styles.slider}// onTouchEnd={(event) => onTouchEnd(event)}// onTouchMove={(event) => onTouchMove(event)}// onTouchStart={(event) => onTouchStart(event)}onClick={onHandleFirstTouch}><View className={styles.activeSliderSet}><View className={styles.activeSlider} style={getAngle()} /></View><View className={styles.origin} id="origin"><View className={styles.long} style={getAngle()}><ViewclassName={styles.circle}onTouchMove={(event) => onTouchMove(event as BaseTouchEvent<any>)}onTouchStart={(event) => onTouchStart(event as BaseTouchEvent<any>)}onTouchEnd={(event) => onTouchEnd(event as BaseTouchEvent<any>)}/></View></View>{/* 背景 */}<View className={styles.sliderBgc} id="sliderBgcId" />{/* 刻度 */}{/* <View className={styles.scaleBgc} /> */}<View className={styles.centerContent}><View className={styles.centerText}>能量档位</View><View className={styles.btn_air_bar}><View className={classNames(styles.btn_air, styles.btn_air_left)} onClick={lose}>-</View><View className={styles.val}><View className="val_text">{state.val}</View></View><View className={classNames(styles.btn_air, styles.btn_air_right)} onClick={add}>+</View></View></View></View>)
}export default HalfCircle

index.module.less

@color-brand: #EBC795 ;
@borderColor:#706D6D;
@sliderWidth:10px;
@radius:150px;
@long: 150px;
@border-radius: @long;.slider {position: relative;padding-bottom: @sliderWidth / 2;background-color: #000;width: 100vw;display: flex;justify-content: center;align-items: center;// 背景色.sliderBgc {width: @long*2;height: @long;border: @sliderWidth solid;border-radius: @border-radius  @border-radius 0 0;border-color: @borderColor;border-bottom: none;}.scaleBgc {width: @long*2 + @sliderWidth *2;height: @long + @sliderWidth;position: absolute;// bottom: 0;// left: 0;border: @sliderWidth solid;border-radius: @border-radius + @sliderWidth  @border-radius + @sliderWidth 0 0;border-color: transparent;border-bottom: none;top: -10px;background-clip: padding-box, border-box;background-origin: padding-box, border-box;background-image: linear-gradient(to right, #000, #000), linear-gradient(90deg, #FFD1B2, #E49E6B);}// 激活色.activeSliderSet {position: absolute;width: (@long) *2;height: @long;// left: 0;// bottom: 0;z-index: 2;overflow: hidden;.activeSlider {bottom: 0;left: 0;width: @long*2;height: @long;border: @sliderWidth solid;border-color: @color-brand;// border-color: transparent !important;border-radius: @border-radius  @border-radius 0 0;border-bottom: none;transform: rotate(-100deg);transform-origin: @long @long;// background-clip: padding-box, border-box;// background-origin: padding-box, border-box;// background-image: linear-gradient(to right, #000, #000), linear-gradient(90deg, #FFD1B2, #E49E6B);}}.origin {width: 0;height: 0;position: absolute;background-color: rgba(0, 0, 0, 0.1);bottom: 0;left: 50%;z-index: 11;transform: translateX(50%);.long {width: @long - (@sliderWidth / 2);height: 0;z-index: 9999;position: absolute;top: 0;left: 0;transform-origin: 0 0;.circle {width: 16px;height: 16px;border-radius: 50%;position: absolute;top: 50%;right: 0;transform: translate(50%, -50%);background-color: #000;border: #fff 4px solid;z-index: 999;padding: 5px;}}}}.centerContent {position: absolute;bottom: 0;left: 50%;transform: translateX(-50%);z-index: 99;margin-bottom: 20px;.centerText {text-align: center;color: var(--q-light-color-text-secondary, var(--text-secondary, #8C8C8C));font-size: 10px;margin-bottom: 25px;}.btn_air_bar {display: flex;align-items: center;.btn_air {width: 30px;height: 30px;border-radius: 50%;background-color: wheat;font-size: 16px;font-weight: 500;display: flex;align-items: center;justify-content: center;}.btn_air_left {background-color: #706D6D;color: white;}.btn_air_right {background-color: white;color: #706D6D;}.val {height: 26px;display: flex;align-items: center;margin: 0 30px;font-size: 26px;font-weight: 700;}}
} 

防抖的工具函数debounce 的详细代码：

import { debounce } from '~/utils/util'

function debounce<T extends Function>(func: T, delay: number): T {let timeoutreturn function (this: any, ...args: any[]): void {const context = this;clearTimeout(timeout);timeout = setTimeout(() => {func.apply(context, args);}, delay);} as any;
}